The invention relates to drinking water dispensers having bottles for storing water and filters associated with the bottles for filtering water flowing from the bottles into the dispensers at controlled rates.
Water dispensers using bottled water have been in use for a number of years. When the water in the bottle has been dispensed, the empty bottle is replaced with a full bottle of water. Bottled water can be natural water or purified water processed at a location remote from the point of use. The processing and handling of bottled water is costly and not economically available to all persons. Community or rural water can be used in the bottles to supply water for dispensers. While community water utilities treat water to meet minimum standards for purity, persons that depend on private wells and other water sources have no assurance of water purity. Filtering devices provided with activated carbon, mechanical filters, reverse osmosis systems and ultraviolet light have been used to treat water. These devices are installed on point of entry locations as water taps or incorporated in portable containers or canteens. Examples of portable containers equipped with water conditioning devices are disclosed by W. A. Sanzenbacher in U.S. Pat. No. 3,392,837 issued Jul. 16, 1968, and W. S. Malson and J. W. Sharpe in U.S. Pat. No. 4,714,550 issued Dec. 22, 1987. These containers cannot be inverted and used with a water dispenser.
A container and filter device is disclosed by G. L. Charbonneau, A. H. Bowler and E. W. Bock in U.S. Pat. No. 5,139,666 issued Aug. 18, 1992. This device includes an air hole in a ring adjacent the filter to allow a flow of air into the enclosed container when the pressure within the container has been reduced by the outflow of filtered liquid. The water pressure in this system that regulates the flow of liquid through the filter, is minimal. The hydrostatic equilibrium exerts virtually no pressure on the filter to overcome the internal flow resistance of the filtering materials. The flow through the filter is reduced to the capillary suction effect between the filtering materials and is, therefore, largely dependent on the filter medium. This may result in a blockage of the filter whereby no filtered liquid can exit the filter. Blockage of the filter may cause air to enter the filter which could lead to oxidization and contamination of the filtering material. Matching the various available filters to this type of filtration system is very difficult.
The invention comprises a bottle for storing liquid, such as drinking water or tap water, for use with a water dispenser having a filter within the neck of the bottle to provide the dispenser with a supply of filtered water at a controllable flow rate without interruption. The bottle has a side wall joined to top and bottom walls providing a chamber for accommodating water. The top wall of the bottle has a neck having a passage open to the chamber. A combined bottle cap and filter holder removably mounted on the neck of the bottle functions to close the bottle neck passage and position a filter in the passage. The filter functions to remove contaminants and other substances from the water as the water flows through the filter from the chamber into the dispenser. The maximum water flow rate through the filter is controlled by the position of an air bleed hole in the bottle relative to the bottom of the filter. To increase the maximum flow rate through the filter the distance between the air hole in the bottle and the bottom of the filter is increased. Increasing the maximum flow rate of the water minimizes blockage of the filter.
The bottle has a tubular neck. The filter has an inlet end open to the chamber of the bottle, an outlet end open to the dispenser, and filtering material located between the inlet and outlet ends for removing contaminants and other substances from the water flowing through the filtering material into the dispenser. A combined ring and filter holder releasably mounted on the neck engages the filter to retain the filter on the neck and close the passage in the neck around the filter. The bottle has a small air bleed hole open to the bottle chamber to allow external air to flow into the bottle chamber to replace water flowing from the chamber and reduce the vacuum pressure in the bottle chamber above the water in the bottle chamber. The air hole is located above the bottom of the filter at a predetermined optimum level to permit a maximum water flow rate through the filter that minimizes filter blockage and prevent flooding out of the treated water dispenser.
The location of the air bleed hole in the bottle also determines the minimum water flow rate through the filter which controls the extraction efficiency of the filter for removal of contaminants from the water. The air bleed hole is located in the side wall, top wall or neck of the bottle. The location of the air bleed hole in the bottle determines the maximum level of water in the dispenser. Preferably the stall level of the water is located adjacent a mid-point of the filter whereby the filtering material is submerged with water. This prevents the filter from running dry and prevents interruption of the flow of water through the filter. The filter can be removed from the neck by removing the holder and filter from the neck. A new filter is then inserted in the holder until the tapered edge thereon engages the side wall of the filter. The filter is placed in the passage of the neck and the holder is turned on the neck. The holder has an annular inside edge that engages the side wall of the filter in a tight fit relation to retain the filter on the neck and close the passage in the neck of the bottle.
The filter is effective to remove contaminants from six to ten or more bottles of water. When the selected number of bottles of water have been filtered, the cap member accommodating the filter is removed from the neck. The filter is removed from the cap member and replaced with a new filter. The bottle and filter of the invention can use community and well water which is filtered to remove contaminants prior to the dispensing into a drinking container.